In our 2011 21V I had Fly High 750's in each of the rear lockers and a long 1100 in the front locker. Ours was a launch so it had a lot of room for ballast under the playpen. Is yours a launch or a sunspot? that will drastically change the amount of ballast you can hide up front. I really enjoyed this setup for surfing and especially for wakeboarding. If I did it again i would probably get one of the long 900's for the front instead, because the 1100 was definitely a bit too long and never could fill up all the way. Hope this helps!